Le Monarque
by quicksilversquared
Summary: A class trip to the butterfly gardens turns nasty after Chloe insults the visiting butterfly scientist and gets him akumatized. Things only get worse when it turns out that the butterfly-themed supervillian can turn people into human-sized butterflies with a single flash of light- and superheros aren't immune to his powers.
1. Chapter 1

_This is my attempt at writing a 'typical' Miraculous Ladybug episode. There are five chapters in total. Enjoy!_

* * *

The day that the entire grade went to the butterfly gardens started out fairly normal. Students were assigned partners from their homeroom classes before they left, just to make sure any temper tantrums from a certain blue-eyed blond were kept at school and not out in public.

The bus came on time, much to the relief of the teachers who were already having trouble containing a couple particularly unruly students. They piled on in a rush, students pushing as they tried to get to the seats in the back of the bus. Others waited for the pushing to stop before boarding.

Marinette, paired with Adrien, sat in front of the bus. Chloe, glaring jealously at Marinette, sat across the aisle. She had not been happy about getting paired with Ivan, who was one of the few people in the class who _wouldn't_ let her get away with doing no work. Nino, paired with Rose, and Alya, paired with Mylene, both sat midway up the bus.

"It's nice to have a bit of a break from the normal schoolwork," Adrien commented as the bus started up. He grinned at Marinette. "I mean, I don't mind schoolwork that much, but the novelty is wearing off a bit, you know?"

Marinette laughed at that, earning another glare from Chloe. Adrien found himself glad that his friend had gotten more comfortable around him after their Megastrike 3 training and hanging out while her uncle cooked. She was a lot of fun to be around, even when her stuttering made a comeback. "The novelty of school wore off for me quite a while ago so no, I don't really know." She grinned again. "I think you're the only one who still gets excited about getting homework."

Adrien could only shrug sheepishly.

"And it's not like we're not going to do _anything_ today," Marinette added. Opening her backpack, she tugged out the packet that Miss Bustier had given them. "We have this entire thing to fill out and then I think we might be getting some other activity to do in the afternoon."

"Still, at least it isn't calculus or Social Science or French Literature," Adrien said with a grin. "New information is interesting. Besides, I've never been to the butterfly gardens before. Have you ever been?"

"Once, when I was really little. Dad has a picture of me with a butterfly on my nose." Marinette grinned. "Of course, he caught me when I was about to sneeze, so my face was all screwed up under the butterfly."

Adrien had to laugh at that, fighting down the urge to ask if he could come over after school to see the picture. He was willing to bet that little Marinette was absolutely adorable.

The bus ride went fast, helped along by Adrien's excitement. It seemed like he couldn't sit still in his seat, resulting in him bumping into Marinette more than a couple times as he squirmed and peered out of the windows of the bus. It soon became very, very obvious that he had chosen their spot just so he would be able to see out the front of the bus and then be the first one out once they got to the butterfly gardens.

"Do you like butterflies?" Marinette asked as Adrien knocked knees with her again as he craned his neck to look out the front of the bus again.

Adrien jumped, startled, then winced as his elbow and the window frame collided. He straightened back up with as much dignity as he could manage. "Not really, but I want to see what it's like. I also just don't like bus rides that much, I guess. The seats are less comfortable than I thought they would be."

Marinette giggled. "Not as nice as the ones in your family car?"

Adrien's cheeks flushed. "I wasn't expecting them to be _that_ good. I just wasn't expecting them to be less comfortable than our desks."

Their conversation was cut short by Miss Bustier rising from her seat, turning around, and loudly announcing that they were only a kilometer away from the butterfly gardens. They could use the bathrooms once they got off the bus, but other than that they were expected to stay with their groups. Adrien listened attentively, despite the fact that they had all heard the exact same instructions before the busses left as well as on the previous day. Marinette, who had heard a million such spiels before on previous trips, slid back down in her seat and texted Alya. Just as Miss Bustier finished talking, the bus driver turned off the main road, heading down a short driveway before pulling to a stop in front of the main building. Immediately the bus filled with the sound of people chatting and feet scraping as everyone jostled to get in the aisle and off the bus. Marinette managed to shove her way out first, followed by an enthusiastic Adrien. She had to pull him forward so that he wouldn't get trampled by the river of students pouring out of the bus while he gazed as the imposing wood house in front of them.

"Are the butterflies in there?" Adrien wanted to know, craning his neck to get a better view. "That's not what I was expecting."

Marinette shook her head. "That's just the research and education center. The greenhouses are behind it. There's an admissions price, so they set it up like this to make sure people pay before they go in."

It took a few minutes before the groups had reconvened again. Madam Mendeleiev led her group in first, followed by Miss Bustier.

They each split off into a different classroom, since the groups had each been assigned to a different biologist from the gardens so that the groups wouldn't get too large and so all questions could be answered. The biologist for their class was tall, thin as a rail, and had mousy brown hair. Overall, he didn't look particularly impressive.

"Mr. Johnson is a visiting biologist from the western United States," Miss Bustier announced as they all settled in the chairs that had been set up. "He'll be doing our presentation today as well as leading our tour of the greenhouses. Don't forget to listen, because you do have that packet to fill in."

From behind Marinette, Alix snorted quietly. "As if we could _forget_ ," she scoffed to Kim. "She's only reminded us a million times."

Miss Bustier either didn't hear or didn't bother to respond. "You'll have two hours to work on your worksheet with your partner and explore the greenhouses and the exhibits by yourself once the tour is done, and then we'll have lunch and listen to a presentation given by all of the scientists here before heading back to school. Remember that _both_ people in a group must work on the worksheet. If your partner doesn't pull their weight, report them to me and they'll lose credit."

Chloe scowled. Ivan looked unbothered.

Miss Bustier beamed at the class. "And if there are no objections, let's start our presentation!"

* * *

Thankfully Mr. Johnson spoke fantastic French, though he _did_ have a bit of an accent. He definitely knew a lot about butterflies and was clearly reigning himself in so he wouldn't confuse people by going too in-depth. Adrien suspected that his clipboard might have a vocab list for some of the butterfly parts and other words that weren't exactly basic French. The first part of the presentation was definitely interesting, with Mr. Johnson's stories about his adventures in studying butterflies. It wasn't something that Adrien ever would have expected to be a particularly interesting job, but apparently the fieldwork could be quite unpredictable.

And then came the section on butterfly identification. They started with the most distinctive butterfly species of the area, which was easy enough, but now they had wandered into looking into some of the less distinctive, more easily confused butterflies. Supposedly they were just doing a light overview of some characteristics to look for.

Adrien was already very much lost, even though they were looking at slides of still butterflies. He could only imagine how difficult it would be to identify live butterflies.

Still, Adrien paid as much attention as he could, even as his classmates' eyes started to glaze over.

"In contrast to the _Pyrgus cacaliae_ , the _Pyrgus carthami_ has markings on the abdomen." Mr. Johnson pointed to the difference on the slides. Adrien squinted. The markings were there, but only faintly visible. Chancing a glance at Marinette, he could tell that she didn't look much less confused, though she was dutifully taking notes as she listened. Mr. Johnson glanced down at his clipboard again before continuing, clicking on to the next slide. "Now, both _Pyrgus cacaliae_ and _Pyrgus carthami_ are lighter in color than several other species in the genus. _Pyrgus cirsii_ , for example-"

Yeah, he was lost.

* * *

Once the section on butterfly identification dragged to a merciful end, they all lined up for a tour of the greenhouses. Adrien was probably more excited than the rest of the class put together, even going so far as to bounce on the balls of his feet as they waited for Mr. Johnson to lead them out.

Marinette had to tug Adrien along once they reached the greenhouses. He twisted his head back and forth as they walked, trying to catch sight of the butterflies that fluttered in between the plants that filled the greenhouses. _This_ was the part of the tour that he had been looking forward to. The greenhouses were a tad on the warm and humid side for his taste, but the plants and butterflies fluttering around more than made up for the slight discomfort.

"How did you like the presentation?" Marinette asked Adrien as they waited for Mr. Johnson to start talking again. The scientist seemed to be busy rearranging his clipboard, looking for his notes for the next part of his talk. "I liked the first part the best."

"Same." Adrien glanced over at the scientist before lowering his voice and ducking his head so that they wouldn't get overheard. "I got _really_ confused with the ID stuff. All of the scientific names? I don't get it."

Marinette could only shrug. "Scientists like scientific names, I guess. They're universal across languages." She grinned. "But I still like common names better. They're much easier to remember."

Nodding, Adrien opened his mouth to agree when Mr. Johnson finally found the page he was looking for and started to more or less read off of the paper. There was a lot of information about why they kept the greenhouses at the temperature and humidity that they did and the plants that were there. Adrien jotted quick notes to himself, unable to keep his entire focus on the scientist when there was so much new stuff to look at. A orange and black butterfly fluttered by, resting briefly on Marinette's arm before fluttering off again.

"Excuse me, sir? What kind butterfly was that?" Juleka asked, raising her hand as she cut across what Mr. Johnson was saying. "The orange and black one."

Mr. Johnson looked a little startled as he was jolted out of the flow of his talk. "Oh. I... I'm not sure, really-"

Chloe scoffed as she rolled her eyes disdainfully. "You're a butterfly scientist and you don't know what kind of butterfly something is? It wasn't even one of those boring ones you were talking about earlier."

Mr. Johnson looked affronted. "Miss, I am a butterfly scientist from the Yellowstone region of the United States. The species of butterflies that you have here are quite different than the ones I see and study back home."

"So? Learn them then." Chloe shrugged, inspecting her nails. "What's the _point_ of you being here otherwise?"

"Chloe..." Miss Bustier started, looking alarmed as she looked between the bored Chloe and offended scientist. She was cut off by Mr. Johnson.

"I can here to study the similarities and differences between the butterflies here and those in my home state. I have primarily been dealing with their diets. I have not had the _time_ to learn the names of all of the butterflies here, especially since I've only been at this garden for just over two weeks."

Chloe only let out a snort.

"All right, I think it's time for you to have a bit of free time to explore the greenhouses and to fill out your worksheets!" Miss Bustier announced loudly before the situation could escalate any further. "If you have any questions, you can ask me or Mr. Johnson or any of the other scientists here."

With a tight smile the students were waved off. Some shot off like they had been shot from a cannon, while others wandered off more slowly. Adrien tugged Marinette off behind him, weaving through narrow paths with overhanging plants. A few more butterflies flew back above them, taking off as they brushed past the flowers they had been resting on.

"In a hurry?" Marinette asked as Adrien found a table among the plants. Flowers surrounded the small alcove.

"Yes- well, no- well, I want to get the worksheet done so that I can explore." Adrien grinned at her sheepishly. "I also wanted to get out of there before Chloe ticked off anyone else."

Marinette let out a sigh of agreement. "I wish Chloe would stop aggravating everyone she meets." Sitting down, she opened her bag and pulled out the worksheets they were supposed to fill out, along with two pencils. "What I would give for just one day of peace..."

Adrien nodded as he snatched the worksheet and flipped through the it, glancing at the questions. There were several he could answer without even looking at his notes. "I hope Miss Bustier explained to Mr. Johnson about how Chloe is. He looked pretty upset."

"I'd be upset too if someone questioned my ability to do my job." Marinette tugged the papers back from Adrien. "Are the questions awful?"

Adrien shook his head. "A lot of these look pretty easy. I was worried that Miss Bustier was going to ask really detailed questions, but she didn't at all."

Marinette shrugged. "She probably only wrote questions that she knew we would be able to answer. They might not cover all of the information during every walk, so she only asked about things that she knew were going to be covered no matter what." She flipped the page over, skimming over the last few questions before she winced. "There's a butterfly identification section. We're supposed to find five butterflies, take a picture of them, and figure out what species they are using the pamphlet we got at the start."

"We might have trouble with the question two from the end," Adrien said as Marinette scribbled in an answer. "It covers the information that Mr. Johnson had been covering when Juleka asked about the butterfly. I don't think we actually finished the presentation."

Marinette groaned as she filled in another answer. Adrien grinned at the frustrated noise and the ridiculous face she made before pulling out his phone and texting Nino. Since several students from the other class hadn't been able to come and the class sizes were uneven, Nino and Rose had been pulled from Miss Bustier's group into Madam Mendeleiev's group. Hopefully his friend had gotten the whole presentation and hadn't been distracted. Seconds after he sent his text, Adrien got a reply.

 _Nino: Bro, you were supposed to listen to the presentation_

 _Adrien: I DID, but our presentation cut off early because Chloe was being Chloe_

 _Adrien: I just need some help with that one question I swear_

There was no response to that one, so Adrien just shrugged and went back to his questions. It was fully possible- no, incredibly probable- that Rose had asked Nino to focus. Adrien would get his response soon enough, hopefully.

"I think the thing about how they mark butterflies was cool," Marinette said as she finished a question, dotting a period with her pencil before glancing over at Adrien. "I never would have thought of using apple-sticker adhesive to put a sticker on a butterfly."

"That was cool." Adrien peered over her shoulder. "Isn't there some question where we get to write down the most interesting thing we learned? I vote we write that down."

It didn't take long for the two of them to plow through most of the questions. Nothing was that hard to answer, though they did have to leave the second to last question blank since Nino hadn't responded yet.

"Time for identification," Adrien sighed as they tucked the paper into Marinette's bag. "My favorite."

"Think we can get away with common names?" Marinette joked as they stood up, ready to start their butterfly search. "Or do we need to copy the scientific name down as well?"

Adrien opened his mouth to reply. Before he could say anything, a scream echoed throughout the greenhouse.


	2. Chapter 2

It only took about thirty seconds for the cause of the screams to become readily apparent. As Marinette and Adrien huddled under the makeshift cover of the plants next to the path, a figure strode over the glass roof of the greenhouse. He was dressed in black spandex with a striking orange and black patterned cape fluttering from his shoulders. A mask shaped like a butterfly covered his face, colored in the same orange and black patterning. He paused right above them before moving away again.

Adrien and Marinette let out twin sighs of relief as he moved away. Seconds later, two screams were abruptly cut off with twin flashes of light and they froze up again.

"We need to get out of here," Adrien hissed, catching Marinette's hand under the leaves and pulling her close to whisper in her ear. "We're pretty close to the doors to the main building. There'll be safer places to hide in there."

"Let's wait until he moves to the next greenhouse," Marinette whispered back. Her face was incredibly focused as her eyes scanned the roof of the greenhouse. "I don't want to get caught."

A few tense minute passed before the akuma got far enough away for them to make a dash for it. Ditching their bags under the bushes by the table, they hunched over and ran. They kept an eye on the ceiling, ready to dive under the shelter of the plants if they caught sight of the akuma again.

Instead, they caught sight of a stranger sight.

In the intersection of three paths two tall green shapes, both tall as a human, blocked most of the path. One was wobbling ominously.

Are those _chrysalises?_ " Marinette gasped, stepping hesitantly forward and reaching out. She yanked her hand back when the green shape shook again. A small crack formed down the side and she jumped back to the safety of Adrien's side. "We should get out of here."

"Agreed." Grasping Marinette's hand again, Adrien tugged her past the cracking chrysalis and towards the main buildings. They sped up as something fell to the floor behind them, neither of them bothering to try to hide the noise from their footsteps as they flat-out sprinted for the doors and crashed through. They skidded to a stop in the atrium, panting as they looked for a place to go.

"The classrooms might be empty," Marinette suggested a bit breathlessly.

"That's too obvious." Adrien spun around, trying to remember what Mr. Johnson had said about how the building was laid out. His shoulders slumped when he realized that pretty much all he remembered was where the bathrooms were. Those would be good (he definitely hid/transformed in the school bathrooms often enough), but there would probably be people hiding there as well. He caught sight of a sign on the wall.

 _Offices._

"Let's go to the offices!" Adrien said, pointing. "The scientists were all out on tour, so the area will be empty."

"And locked, probably."

"Maybe not. And there might be more rooms on the way." Adrien led the way down the narrow hallway. He kept his ears pricked for any sounds of pursuit as they hurried away from the main atrium. If they got trapped in the rat maze of the back hallways, they would be in a whole world of trouble.

Of course, maybe the akuma showing up would be a good thing. He had to get away from Marinette to transform, but he hardly wanted to ditch her before she was safe.

Up ahead of them, a door was cracked open just enough for them to see it as they ran down the hall. They dove into the room, closing the door behind them.

Marinette immediately made a beeline to the window, peering out around the closed curtains. "The akuma is still out there and there's something big moving around in the greenhouses."

Leaning over Marinette, Adrien squinted outside. Sure enough, the supervillain was still on top of the greenhouses, standing tall and proud as he watched something in the greenhouse they had just escaped. The _something_ was large and dark, flopping in and out of sight behind the plants.

More movement further down the line of greenhouses caught Adrien's eye. He craned his neck, trying to see without disturbing the curtains. A door burst open at the far end of the greenhouses and two girls burst out. It took only a moment for Adrien to recognize who they were.

Alya and Chloe.

Adrien only had a moment to try to puzzle out why the two had been together before something burst out of the still-swinging door behind them. It was large, the middle as long as Alya was tall, and with gigantic greenish wings edged with pink.

"It's a giant _butterfly_ ," Marinette gasped before Adrien could say anything. "Where is he getting _butterflies_ from?"

"They must come out the chrysalises," Adrien managed. His throat was tight as he watched Alya and Chloe tear across the lawn. They clearly hadn't noticed the supervillain standing on top off the greenhouses with all of their focus on getting away from the giant butterflies, but the butterfly-themed supervillain had definitely noticed them. He watched as they drew closer, Alya running faster than Chloe.

Then, in a movement almost too fast to follow, he struck. Twin flashes of light zipped towards Alya and Chloe, one yellow and black and the other a reddish brown. When the light cleared, two chrysalises stood on the lawn.

 _Oh no_.

The supervillain smirked before turning his gaze towards the main building. Adrien yanked Marinette back from the window, pulling her under the cluttered desk. His heart was beating loud in his ears, racing as he tried to quiet his breathing even though the supervillain wouldn't be able to hear him. They weren't going to be found, he was pretty certain of that, but he wanted to make sure. The supervillain hadn't been looking directly at them and he wanted to keep it that way.

A minute passed in dead silence. Adrien kept his gaze locked on the odd, almost dinosaur-shaped stained on the underside of the desk as he tried to keep his breathing even and strained his ears for any sign of an approaching akuma. He was definitely glad that Marinette seemed to be keeping calm, but then again she always kept a level head during attacks. If he had been with some of his other classmates, they probably would have been found by now. While panic wasn't quite as common of a response to akuma attacks as it had been when the attacks started, some akumas just provoked that kind of response.

"I think we're safe," Marinette whispered, wriggling out from under Adrien and the desk. She rose up cautiously before peeking outside again. "It's clear. The chrysalises are cracking, though."

Curious, Adrien crept back up to join her. It would definitely be helpful to know what the akuma was capable of once he finally got to meet up with Ladybug. He watched He and Marinette watched in horror as the green-brown chrysalises broke away to reveal dark, crumpled wings and an insect's face, magnified a thousand times over. The wings unfolded slowly like a battered umbrella, straightening out and starting to dry in the midday sun as they crawled out to rest on top of the broken shells.

 _Butterflies._

He had to get out there.

"Stay here," Adrien ordered as he straightened up and away from the window, holding Marinette back with one hand on her shoulder. "It's not safe out there."

"I _know_ tha- wait, where are you going?" Marinette demanded as Adrien crossed the room and bolted out into the hallway. "Adrien!"

Adrien winced as he darted away from the room. Marinette thankfully hadn't followed him, but he'd have to explain himself later for sure. Adrien hadn't liked ditching his friend like that, but he hadn't had any other option. If Ladybug arrived soon, he would have to be ready to debrief her before she could get hit.

He could only hope that she knew about the attack and would arrive soon. He didn't want to face this akuma on his own.

* * *

Chat Noir hid in the trees nearest to the main building, keeping one eye on the akuma and one eye on the creatures that had previously been Alya and Chloe. They had very clearly become butterflies and were now sunning themselves as their wings unfolded and dried out. He could see other human-sized butterflies fluttering around in the greenhouses, trapped with the doors closed.

"Oh, those are terrifying."

Chat Noir jumped a foot in the air when Ladybug spoke from right behind him. He landed and immediately had to scramble to keep his balance on the branch and not fall to the ground. He turned as best he could without falling to flash Ladybug a wide smile. "My Lady! I was wondering when you would show up."

"I was with a friend and couldn't figure out how to get away for a bit." Ladybug inched closer, watching as butterfly-Alya and butterfly-Chloe took off into the air, fluttering in circles above the greenhouses. " _Ugh._ Of course this had to happen on a day when there were school groups here. There's a giant group from the retirement home in the back garden as well." She paused, grimacing. "Well, there _was_. The whole area is filled with chrysalises and abandoned walkers now."

Chat Noir winced. "At least the butterflies seem pretty harmless. I haven't gotten close to them at all, but they're just flying around being butterflies."

"For now." Ladybug shifted, her eyes scanning the area around them in a pattern Chat knew well. She was looking for the supervillain, making sure that they didn't get caught by surprise. "Have you seen the butterfly guy?"

"Earlier, yeah. Not recently."

"Yeah, I lost track of him earlier." Ladybug let out a frustrated huff. They fell into silence as they watched the scene in front of them, both trying to figure out a plan of attack. They dropped to the ground, creeping closer to get a better view without startling the resting butterflies. When they were only a meter out of the forest, everything changed.

The two butterflies closest to them froze up, their wings pausing mid-flap. Then they turned in unison to face the two heroes. Further behind them, more butterflies did the same.

Chat Noir and Ladybug froze up as well, eyes locked on the suddenly not-so-harmless butterflies. They had a brief staring contest before the butterflies lurched forward.

The superheroes bolted.

There weren't many tall buildings in the area around the butterfly gardens, which definitely hampered Ladybug's movement more than Chat Noir's. She finally ended up latching onto his back, clinging to him and keeping an eye on the butterflies following them as they made a beeline for the more familiar territory of the city. On the way there, they learned more about how dangerous their opponents were.

On the plus side, most butterflies were not particularly fast. There still quite a few butterflies trapped in the greenhouses, unable to escape through the doors without help. For whatever reason, the supervillain hadn't seemed particularly inclined to release his newly-transformed subjects.

On the other hand, some of the butterflies _were_ fast. Butterfly-Alya and Butterfly-Chloe sped along, wings pumping as they pursued the superheroes. They dodged in and out of the trees houses and, once they reached the city proper, between the buildings.

"Maybe we shouldn't've gone back into the city," Chat Noir panted as they swung over a group of gaping citizens. "If the butterfly dude follows us here and starts turning people, we're in trouble. I don't know how we'll fight a butterfly army _and_ a supervillain at the same time."

Ladybug grimaced as she lassoed a chimney. "I forgot about that."

"Yeah, my first instinct was just to get up high on familiar territory. The forest was putting me on edge." Chat Noir dodged behind another chimney as he was dive-bombed by one of the butterflies. "I can't believe that this guy can turn people into butterflies. It's insane _._ "

"I can't believe that my life is even this insane." Ladybug paused to try to whack Butterfly-Alya out of the air with her yo-yo. The reddish-brown butterfly didn't even appear fazed. "Is it just me, or are the akumas getting stranger?"

"Maybe Hawkmoth can't do the exact same thing twice," Chat Noir suggested a bit breathlessly. "So now he's picking on people that are upset about unusually specific things."

"Stupid butterfly man has too much time on his hands if he has the spare time to come up with all of these weird powers." Ladybug sent a downright poisonous look at the overgrown butterflies chasing her. "I wonder how his powers work, actually. Does he come up with the outfits and the powers? If he does, he needs to take some fashion classes. Some of the outfits he makes are straight-up hideous."

Chat Noir snorted as they narrowly evaded another dive-bombing. He could remember a few absolute fashion disasters. The Bubbler's outfit looked like something dreamed up by a three-year-old. Others, while better, were still more than a little cringe-worthy.

Now wasn't a good time to think about that, though. Neither he nor Ladybug could afford to be distracted and get caught by the butterflies chasing them. They didn't know what might happen if they were caught by the butterflies and to tell the truth, Chat Noir was perfectly content to keep it that way.

After all, curiosity _killed_ the cat. He preferred staying alive, thank-you-very-much.

For ten whole minutes Ladybug and Chat Noir did everything they could to shake the giant insects. They ran over building rooftops, zig-zagging between blocks to no avail. They shot up into the sky on Chat Noir's baton, only to have the butterflies follow them all the way up. They landed in the Princess Stadium and ran through the doors only to find the butterflies waiting on the other side.

By the time Ladybug and Chat Noir managed to shake off Butterfly-Alya and Butterfly-Chloe, the butterfly army had expanded exponentially and the supervillain had a name- _Le Monarque_. The streets were full of the human-sized monstrosities and there were no normal people to be seen. A few more chrysalises in the middle of cracking provided the only clue to which direction the supervillain had headed.

"There's no way we can even get _close_ to Le Monarque with his army," Ladybug groaned, nibbling on her lip as she and Chat Noir peered down at the chaos from their hiding spot. "We need to find some way to neutralize the butterflies before we can get to him."

"I'd say use Lucky Charm, but there's no way we could take down the entire army in five minutes." Chat Noir tugged on his tail anxiously, trying to collect his mind enough to think. It was always a difficult task with the adrenaline racing through his body. Even as a superhero, he was still and danger and painfully aware of it. "But what else can we do?"

"We need to get people off the streets so that they don't get turned into butterflies," Ladybug said after a second, squaring her shoulders as she flipped into the steely hero mode Chat so admired. "No driving, no walks, doors locked and windows closed. Even if we can't decrease his army, we can keep it from getting any larger."

"Are you calling the news station?"

"And the mayor, I think. Or maybe the police department."

"If you tell the police station that Chloe was affected, they'll let the mayor know for sure."

Ladybug let a small smile slide onto her lips. "Or they'll keep mum because they don't want to deal with the mayor." She called them anyway, hissing into her yo-yo as Chat Noir kept watch for any butterflies coming too close. Seconds after she hung up, sirens blared through the city streets. Butterflies swarmed up into the air, disturbed from their perches by the loud sound.

"Are they going to explain the siren?" Chat Noir asked as they huddled further into the safety of their nook.

Ladybug nodded, leaning forward so that she could speak directly into Chat Noir's ear. He tried to ignore the proximity and stay focused on the task at hand. "The news station is doing an emergency broadcast. They're putting an emergency curfew in place until this akuma is defeated."

Chat Noir made an approving noise, flinching as a pale orange butterfly fluttered past. Once he was sure it was a safe distance away, he twisted around to talk to Ladybug again. "What should we do now? Should we lay low for a bit and try to figure out his weaknesses? Maybe there's a way to release them, like with Dark Cupid's spell."

Ladybug looked thoughtful, her eyes going a bit distant as she thought. "Maybe."

"Would whatever you did then work now?"

Ladybug looked mildly alarmed before shaking her head. " _No_."

"Will you ever tell me what you did?" Chat Noir asked hopefully. She refused to tell him anything, which mean that it was bound to be interesting.

"NO."

Chat Noir pouted, giving her his best kitty eyes. "Why not? It's not like you kissed the evil out or whatever." He didn't notice the stiffening in Ladybug's shoulders as he continued. "But how did you figure out what to do?"

"Something you said made me think- wait." Ladybug's eyes locked on him. "We need to get closer. Maybe Le Monarque will say something and give us a clue."


	3. Chapter 3

"I am _so_ glad that our weapons come with audio and zoom," Chat Noir announced as the two heroes crouched under a window in the Grand Paris honeymoon suite. It hadn't taken much to persuade the mayor to let them take refuge in the hotel once they showed up (though he had taken a excruciatingly long time to respond to their knocking initially), and as it turned out, the hotel was a perfect hiding place. Le Monarque prowled the streets below them, but they were safe behind closed, curtained windows and locked doors.

Still, they weren't taking any chances. Instead of standing in the window and watching, they both held their respective weapons aloft in the window as they watched the scene unfolding on their screens. The supervillian currently looked irritated with the lack of civilians to turn into minions, and his oversized butterfly army fluttered agitatedly around him as he snarled.

"I didn't realize how many people he had gotten to," Chat Noir said as he watched a few more butterflies join the core group around Le Monarque. "I wonder if he let the ones in the greenhouses go or if these are all new ones."

"He seems to be able to call them to him. They were more spread out and disorganized before." Ladybug made a face, sliding all the way to the floor. "Do you think if we hide for long enough he would let them wander off again?"

"It's more likely that he would just start breaking into buildings to transform people, I think. It's a wonder he hasn't already started doing that."

Ladybug shuddered at the thought before twisting back into a crouch and holding her yo-yo back to the window to survey the street below. She had to crane her neck to see the screen because of the angle, but the sound carried through well enough.

" _What, does nobody want to see my butterflies?"_ the akuma taunted. The fact that the streets were empty and there was no one to hear him didn't seem to deter him at all. " _Are you worried that you won't be able to identify them?_ "

 _"Identify?_ " the two superheroes gasped at once.

"That's it, of course!" Ladybug exclaimed. "We identify what species someone is and they could turn back!"

"Problem," Chat Noir said immediately, holding up a clawed finger and wincing as he remembered that morning's class on butterfly identification. He really wasn't in any hurry to put those half-remembered hints to the test"I'm not good at identifying butterflies."

"I don't think the butterflies are even from around here." Ladybug eyeballed the orange and black butterfly fluttering above them before slumping. "I'm no expert, but I don't recognize them at all."

"Maybe they're from another country," Chat Noir suggested, trying to think. With a jolt, he remembered the upset butterfly biologist. Of course! The man was from America, where the butterflies were different. The only question was how to tell Ladybug where Le Monarque was from without sounding like he was there? Then the akuma yelled something frustrated, his accent blurring the words, and he perked up. _Aha. Accent._ "Doesn't the akuma's accent sound a bit like Jagged Stone's? He might be American."

Ladybug straightened up, expression brightening. "Of course! He must be that visiting butterfly specialist at the butterfly gardens. I think that he said that he's from somewhere in the western parts of the country. So we just need to find a guide to the butterflies of the western U.S. and then we can use that to start turning people back!"

"Problem," Chat Noir said again. "We're in France. Where are we supposed to find a book like that?"

* * *

"Do you break and enter often?" Chat Noir asked suspiciously as they tore along the hallways of the butterfly garden building. "You are _far_ too comfortable with doing this."

"I only do it when I have to." Ladybug glanced down another hallway before turning and heading down it. It took a second for Chat Noir to recognize the hallway as the one he and Marinette had escaped down earlier in the day. "Besides, we did try the bookstore first. Break-and-enter wasn't my first resort this time."

"'This time'?" Chat Noir echoed incredulously as they skidded around a corner. "What do you mean this time? This has happened other times?"

The faintest hint of a blush colored Ladybug's cheeks as she ran. "No comment."

"Mind explaining where we're going?" Chat Noir asked, deciding to drop the previous subject for the time being in favor of figuring out what Ladybug's plan was. He couldn't quite follow her line of thinking. If the bookstore hadn't had the book that they needed, why on earth would they be able to find one in the offices? Most of the doors were locked, making exploring even more difficult.

He knew. He had tried more than a couple of the doors earlier, both when he and Marinette were looking for a place to hide and when he was looking for a place to transform.

"I'm looking for a campus map, or maybe a contact list for the scientists here. I want to know where the visiting scientist is staying. I tried looking it up on my yo-yo earlier, but it doesn't do nonpermanent residences."

Chat Noir's head spun as he tried to keep up with Ladybug's line of thought. Then he caught on, just as Ladybug swerved into an open, empty room. "You think the scientist would have brought an identification guide with him?"

Ladybug nodded as she pounced on the desk in the office and started shuffling through the papers there. When she didn't find what she wanted there, she tugged out one of the desk drawers and rifled through that. A map of the gardens came out first and, after only a scant few seconds, was tossed aside. It floated under the desk, revealing something written on it. When Ladybug didn't notice, Chat Noir decided to investigate.

Ducking under the desk, Chat Noir stretched to snag the paper with a claw. As he pulled it closer to himself and started to straighten up, an oddly shaped stain on the underside of the desk caught his eye. It looked like a dinosaur.

This was the same office he had left Marinette in.

Chat Noir straightened up in a rush and swung around, eyes scanning the room for any clue for where his friend might have gone. She wasn't in the room, that was obvious. There wasn't a closet to hide in and no one was under the desk. For a long second, he panicked. Was Marinette all right? Where had she gone? If she had gone after him and gotten hit because of it, he would feel awful.

But there was no time to think about that now. If she had been hit, then there was nothing he could do now besides help Ladybug find what she needed and hope that her plan for de-butterflying (for a lack of a better word) worked as she thought it would. Pushing his worries aside, Chat flipped the map over to look at the backside.

 _Monsieur Elliot Johnson- Guest cabin no. 2._

Flipping back to the other side, Chat Noir scanned the page. Sure enough, tucked away behind the greenhouses and outdoor gardens, were five small cabins.

 _Jackpot_.

* * *

Getting out to the cabins without being detected by any of the lingering butterflies was a feat in itself. While most of them had stayed in the city with Le Monarque, a few still lingered. Several rested on the shattered remains of the greenhouses, while several others sat on top of the main building. Ladybug had ended up borrowing a man's black overcoat from the coat rack to be less conspicuous as they dropped from a window and dashed into the forest before circling around to the back. From there, it was mostly a matter of getting to the cabins without getting lost. They had to be far enough in to not be easily detected from the gardens, but not so far as to lose sight of the gardens and overshoot the cabins entirely.

And then the cabin door was locked.

"We don't have _time_ for this," Ladybug grumbled, testing the knob once more before stepping back and giving the door a poisonous look. Before Chat Noir could suggest anything, she raised her leg and kicked the door open with a neat roundhouse kick, snapping the lock cleanly off. Stepping inside, she started prowling around. Chat Noir followed more cautiously, glancing around the cluttered, cramped bedroom.

It was immediately obvious that whoever lived here was only in the room temporarily and didn't care about keeping the room neat. A suitcase sat half-unpacked at the foot of the bed. Several shirts and jackets hung in the narrow closet. The bed's covers were rumpled. A couple of books and loose papers sat on the desk, while a overflowing backpack was jammed under the chair. Ladybug pounced on the desk immediately, scanning the papers with eager eyes. Seconds later, she sat back, disappointed.

"It's all about French butterflies. There's not even a single paper about American ones."

Chat Noir shrugged. "That makes sense, I suppose. He came here to study our butterflies, not the ones he could see back home."

"But where else are we supposed to find a book on American butterflies?" Ladybug was tugging anxiously on her pigtails. "We can't exactly run around with a laptop and I don't remember what region of the country he comes from!"

"Maybe he has something that has his address or references his research," Chat Noir suggested, squatting as he reached for the giant backpack and started to unzip it. "Do you want to dig through the suitcase? Maybe he has something in there."

Ladybug nodded and dashed across the cramped room. Seconds later, there was a crash as she turned the suitcase upside down and dumped everything out before starting to scrabble through it.

"You couldn't just dig through the suitcase nicely?" Chat Noir asked in amusement, looking up from the backpack.

"There was dirty underwear on top. I wasn't going to touch it."

"It might have been clean but just not folded," Chat offered helpfully as he yanked out a pair of binoculars, a handful of snack bars, a water bottle, and three tubes of sunscreen out before he could uncover the books inside the backpack. He tugged out the first two and tossed them aside when they turned out to be a romance novel and a guidebook of Paris and the surrounding area.

"No, it was _definitely_ dirty. I could tell." Ladybug sounded disgusted.

 _That_ was far more than Chat Noir ever needed to know about Mr. Johnson. He probably would have dumped the suitcase as well. Making a face at the mental picture Ladybug's words had conjured, Chat Noir continued digging. There was a French-English dictionary, an American newspaper from a month prior, a tangle of charging cords of all lengths and colors, several field notebooks, and finally, at long last, a guidebook to the butterflies in the western U.S.

* * *

On the positive side, the guidebook was definitely for the right region. Right off the bat, Ladybug and Chat Noir found species in the book that looked kind of like the ones they had seen outside. It would also be easier to look for patterns on the often-sluggish human-sized butterflies than it would be on a normal butterfly.

On the other hand, identifying butterflies was still _really difficult._ They were still moving around, ducking in and out of sight before the two superheroes could figure out what species a particular butterfly was. They had briefly entertained the idea of finding a scientist from the gardens to help them, but it seemed that all of the scientists had either been turned into butterflies or were really, really good at hiding.

Still, the task wasn't _impossible_. After a good ten minutes of trying to track butterflies while simultaneously looking them up and staying safely tucked out of sight, they managed to stumble upon a still-drying butterfly on its chrysalis.

"It looks like this one, doesn't it?" Ladybug asked, passing the thin book over to Chat Noir and pointing at a picture. Chat Noir nodded enthusiastically.

"It is! That butterfly is a-" he paused, consulting the guidebook again "-a _Rocky Mountain Dotted Blue_!" His pronunciation of the English name was a tiny bit mangled, probably, but understandable.

Nothing happened.

"Maybe it's the wrong one," Ladybug muttered, snatching the book back and comparing the picture to the fluttering creature. Frowning, she flipped to the surrounding pages. Those pictures _definitely_ didn't match, meaning that there was only one species that the butterfly could possibly be. "It _looks_ right." A pause. "Maybe we aren't supposed to use the English name."

Chat Noir's brown creased in confusion. He'd only seen one name for the butterfly in the book. "What other name is-?"

Before he could finish the question, an ominous buzz came from overhead. The heroes looked up in unison.

Above them, surrounded by half a dozen butterflies, was Le Monarque.

"Go go go go go go _go!_ " Chat Noir blurted, snatching the book back and shoving it under his belt before grabbing Ladybug's hand and pulling her out of their hiding spot. They sped off, Ladybug with her yo-yo and Chat Noir vaulting his way from rooftop to rooftop with his baton as fast as he could manage. Le Monarque and his minions followed in hot pursuit.

They had just managed to put some distance between them and the akuma when everything fell apart. As both heroes reached the end of a building, a yellow and black butterfly appeared right in front of them, making both of them swerve. Chat Noir went to the left, while Ladybug veered right. Chat Noir ran blindly, his only goal to get as far away from Le Monarque as possible so that they could try to de-butterfly people again. He and Ladybug would be able to meet up again quickly once they shook off the butterflies.

Just as Chat Noir dodged behind a chimney, a flash of light and a squeal came from his right. He ignored it, fully focused on getting to safety. He only stopped when the sounds of pursuit dropped off abruptly, making him skid to a confused halt. Glancing around, and then turning in a full circle, Chat Noir blinked in two parts confusion and one part terror.

Because behind him was no Monarque, no monster butterflies, and no superhero partner.

* * *

 _A/N: And so the story actually gets interesting :D Any guesses on what happens next?_


	4. Chapter 4

This was probably the textbook definition of _very bad._

No, scratch that, this was _definitely_ the textbook definition of _very bad_. Le Monarque had a giant butterfly army, Ladybug was MIA, and Chat Noir had not a single clue what he should do. He didn't even have a Lucky Charm to guide him. Instead, all he had was a slightly crumpled book.

Yeah, _very bad_ pretty much summed it up.

"I can't believe she got hit," Chat Noir moaned as he paged through the book again. It was looking significantly worse for the wear compared to when he pulled it out of the biologist's backpack. "And I can't believe that the detransforming thing didn't even work."

It was unfair, that was what it was. According to what the akuma had said, it had certainly _sounded_ like identifying a butterfly's species should make it revert back into a normal civilian. His pronunciation hadn't been _that_ bad, he was positive (even if English pronunciations could be stupid at times), so saying the name _should_ have worked, right?

Except they were in France, and Hawkmoth was French. Maybe that had been what Ladybug had been about to say when she was interrupted. They should have translated the English name into French, and _then_ it would work.

If it didn't, he was very much screwed.

"All right, time to find a butterfly," Chat Noir muttered, slipping out of his hiding spot and looking around. As much as he just wanted to sulk for a while, that wasn't an option. "An obvious one preferably, and maybe it could be exceptionally slow and sleepy. That's not too much to ask, right?"

 _Yeah, not likely_.

Surprisingly, it actually didn't take that long to find a few butterflies. As the day got warmer and the sun peeked out between the clouds, quite a few of the butterflies had decided to stop flying around aimlessly and go sunbathing instead. Their wings moved even slower as they soaked in the sun, shifting slightly to better soak in the heat. Chat Noir grinned, settling behind the peak of a roof after making sure the coast was clear behind him. With any luck, he could get this entire area cleared in short order.

His power wasn't luck, but he was choosing to ignore that.

There were ten butterflies clearly in Chat Noir's sight range, giving him a good selection to choose from. They were all mostly white, meaning that he would be able to find all of them listed in the same short section of his butterfly guidebook. If one proved hard to identify, he could always choose another without having to page endlessly through the guidebook. Honestly, it was almost like Ladybug's good luck had rubbed off on him for a change.

Glancing around one more time to make sure that there weren't any butterflies behind or above him, Chat Noir tugged out the identification book again, wincing at the creases it had gotten from him running, jumping and twisting. Hopefully Ladybug's Miraculous Healing Light would fix it.

Hopefully there would _be_ a Miraculous Healing Light.

Shaking the thought away, he started paging through the book. It was easy enough to find the section with the white butterflies, and he had picked out the most distinctive butterfly so that there would be no chance of him getting the species wrong. He still spent a solid minute looking between mutant butterfly and picture (checking his surroundings every so often as well, of course) and making sure that his translation would be as accurate as possible before he was ready to try his theory out.

It was go time.

"It's a _Stella Orangetip_ ," Chat Noir said in French, keeping his voice low as he pointed a clawed finger at the butterfly. He repeated the name in English, just to be sure.

Nothing changed.

Chat Noir's face fell as he checked the guidebook again, making sure that he was looking at the right page. He definitely was, it was impossible to deny that, but it just _wasn't working._ Completely and utterly discouraged, Chat Noir sunk back down onto the rooftop, his face buried in his hands, feeling like a complete and utter failure.

If there wasn't a way to turn butterflies back into people, the whole trip to go find the guidebook had been a waste. It was time squandered that they couldn't get back, it had probably given Le Monarque free reign to expand his butterfly army even with the alarms in place, and all it had accomplished was getting Ladybug captured and turned into a butterfly. He had never found himself in this position before, with Ladybug captured and the akuma still going strong. He had fought akumas one-on-one, sure, just biding his time and trying to limit their damage until Ladybug heard about the attack and could arrive. He had served as a distraction as Ladybug thought up a plan. In both cases, she usually could swoop in at just the right time to save him.

He didn't have that luxury this time. If he got hit, he was done for. Hawkmoth would win, unless other superheros turned up out of thin air and managed to take Le Monarque down.

Sighing, Chat Noir rearranged his limbs on the roof and stared down at the scenery below him. It took a second for him to recognize the bakery that Marinette's parents owned, locked up tight with the shades drawn. Marinette's room was similarly locked down from what he could tell, no doubt by her parents since Marinette wasn't at home.

He briefly wondered how they would have done together with their butterfly identification assignment. Neither of them had been looking forward to it. She had been joking about it before the akuma struck.

Chat Noir straightened up as though he'd been shocked. There was a memory there that was bugging him, something Marinette had said.

 _"Scientists like scientific names, I guess. They're universal across languages."_

And then, later, right when they were going to start the identification section-

 _"Think we can get away with common names?"_ Marinette had joked. _"Or do we need to copy the scientific name down as well?"_

 _Scientific names._

He would have to buy her an ice cream cone in thanks if this actually worked.

Re-energized, Chat Noir wriggled his way back up the roof. He picked up the guidebook from where he had abandoned it, thankfully open to the page he had been on before, and glanced down. Sure enough, there it was. The scientific name. His very last chance.

"Okay," he whispered, careful not to attract the attention of the still-dozing butterflies below him. "It's a _Anthocharis stella_."

Barely daring to breath, Chat Noir looked up.

The butterfly vanished in a flash of orange and white smoke, sending the civilian tumbling the short distance to the ground. The elderly woman who had previously been a butterfly looked around, disoriented, before hobbling away into the nearest building as fast as she could go, clutching her orange shawl around her shoulders.

A grin slowly spread across Chat Noir's face.

"It worked," he whispered, then louder, "IT WORKED! HA!"

Grinning, Chat Noir set his sights on the next butterfly, one with striking black and white wings. It was easy enough to identify as a Pine White, which meant that it wouldn't take long to free it and then clear the area.

Maybe this wouldn't be so hard after all.

This was definitely hard.

Le Monarque's army was _everywhere._ While the butterflies didn't look like they posed much of a threat while they sunbathed in the warm midday sun, Chat Noir knew perfectly well how quickly they could get stirred up. If the de-butterflied civilians made too much of a fuss, it would disturb the others resting nearby and Chat Noir would find himself once again pursued by several monstrous butterflies if he didn't take off right away. A couple times he only just managed to notice a butterfly coming up behind him before it caught him.

Simply put, working alone was _hard._ Working as part of a team was far safer and easier as well.

Which brought him to his current goal: Finding Ladybug and getting her back.

It was hardly an easy task. Thanks to the large number of people in the butterfly gardens and the surrounding area, Le Monarque's army numbered around two hundred. After two hours of identifying, Chat Noir had managed to free maybe seventy-five of those people, and it was getting steadily more difficult to get more than one at a time as he drew closer to where Le Monarque was. If he was really unlucky, Le Monarque would be keeping Ladybug (well, Ladybug's butterfly form) close to him. He would likely only be able to detransform one before having to run, so he had to get it right.

To improve his chances, Chat Noir was trying to find a pattern- _any_ pattern-that might help him find Ladybug. It involved a lot of sitting and staring and not looking particularly superhero-y as he puzzled over the few pieces of the puzzle he had managed to figure out.

Chloe's butterfly form had been yellow, as had Rose's. Both girls were blonde and had been wearing yellow. Nino had become a dark brown butterfly with orange spots, almost mimicking the ones on his shirt. Nathaniel had been orange. Other civilians that he didn't recognize had followed the same pattern, with either their clothes or their hair (or both) matching their butterfly colors.

So it stood to reason that Ladybug would follow that pattern as well.

Her hair was jet-black, appearing almost blue in some light. Her suit, of course, was red. Since there were no black butterflies that he could see, his Lady was probably one of the ones patterned with a brilliant red-orange.

The problem was that there were far too many of them. Red was a popular color in Paris at the moment.

"I should have stuck around to see what she came out as," Chat Noir grumbled as he came upon an entire group of reddish butterflies. Quite a few were identical, suggesting that it might have been a school group with matching shirts, likely out on a field trip. "It would make this easier."

It took only a couple minutes to clear the group out, since the kids tended to land and then stare in wonder (or terror) at the human-sized butterflies around them instead of running away screaming. It definitely didn't hurt that so many were the same and so Chat Noir could clear a whole chunk of them in seconds.

Still, groups like that were rare. Far more often, he found butterflies in mixed groups, no two alike and more often than not covering a the whole spectrum of colors. If he didn't find Ladybug (a which was looking increasingly likely, because Le Monarque had hit a whole lot of people, the whole de-butterflying process was slow-going, and he had no idea whether or not Le Monarque was finding more people to turn), Chat Noir might have to face Le Monarque himself.

He wouldn't have backup unless he could find a trustworthy-looking bystander to identify him back to himself if things went sour, and he wouldn't be working as part of a team, but he could probably manage to get close enough to identify and destroy the akumatized object. The akuma would be released, and, if he was remembering their first fight correctly, most things went back to normal after the akuma was released from its cursed object. He would just have to hold on to the akuma until Ladybug showed up. He wouldn't think about what would happen if the akuma's effects _didn't_ wear off; perhaps sticking the cursed butterfly into a jar and then consulting Plagg would be an option.

Yeah, he was in trouble. But with classes (presumably) cancelled for the afternoon since half of their class was still missing, it wasn't like he had to rush. He could take things nice and slow.

The only problem? Cats weren't known for being particularly patient, and Chat Noir was hardly an exception. He liked seeing results fairly quickly.

"Stupid butterflies," Chat Noir muttered ten minutes later as a butterfly fluttered out of sight before he could finish figuring out what it was. It was the third time it had happened in a row, which was not improving his mood at all. His stomach had just started growling, reminding him that he had definitely missed lunch, and he would probably have to drop his transformation soon to let Plagg recharge; even though he hadn't used Cataclysm, the kwami still got tired and needed to recharge after a long transformation, which this definitely was.

Part of him wanted to call up the news station and see if he could get any civilians on the job. They could look up Rocky Mountain butterflies on their phones and computers, maybe, and identify anything outside their windows. It definitely had the potential to backfire, though, with the number of civilians that seemed all too willing to risk life and limb to do anything to help a superhero out. Civilians might decide to go out in the streets, risking being turned into butterflies themselves, or think that they were safe in their cars even though Ladybug had told the news station that Le Monarque's powers could go through glass. They had already confirmed that in one of the worst ways when the mayor got hit when passing by an uncovered window. While it had been a bit funny watching the staff chase the large butterfly out the door, it was definitely not good.

No, it was better to do it himself than to risk dragging any civilians into danger. He was doing pretty well despite the setbacks that kept smacking him in the face, and he could trust himself not to mess up too badly.

Hopefully, at least. He had messed up pretty badly in the past, but he could be pretty careful. He was being pretty careful right now, seeing as he hadn't been chased for quite a while.

Grumbling, Chat Noir pulled himself back up to his feet. Maybe he was going about this the wrong way, but there was no Ladybug to tug him back on the right track. If she were here, she'd say...

Well, if she were here then he wouldn't be in his current predicament, so that didn't exactly work.

But if she somehow _was_ here, she would tell him not to focus on something that could so easily fall through. If she were being kept close to Le Monarque, it would be easier for _him_ to get in close without being detected if there were significantly fewer butterflies.

Basically, he just needed to keep on clearing out the butterflies, _maybe_ just focusing on the reddish butterflies a bit more if he had a chance.

So he did. Taking a deep breath and only eyeballing the shuttered restaurant on the corner a little longingly (it was _definitely_ past lunch now), he headed after the butterfly that had just flown away from him.

No one said the work of a hero had to be glamorous.

* * *

 _One more chapter to go! Reviews are always appreciated._

 _Somewhat of a filler-y chapter (my apologies) but otherwise the last chapter would have been 3x the length of the others._


	5. Chapter 5

The city had been on lockdown for over three hours by the time Chat Noir (recharged, after a particularly dangerous sprint through the streets to find a secure enough hiding spot) managed to work his way into the particularly dense section of butterflies surrounding the Le Monarque. He had to be on incredibly high alert now, since there was such a high chance that he would be spotted. Now more than ever he missed his partner. Having someone to watch his back was _really_ nice.

Speaking of which, there was still no sign of Ladybug. Chat Noir had de-butterflied what felt like dozens of red butterflies by that point. He had been particularly excited to find a Painted Lady because, well, Ladybug was his _Lady_ and it made sense, but it ended up being some minor royalty from England who was none too thrilled to have been turned into a giant flying insect.

Chat Noir was pretty certain that her screams were still ringing in his ears.

While most of the butterflies that he stumbled upon were random citizens caught in the wrong place at the wrong time, others were people he recognized. Chloe, Rose, Nino and Nathaniel had all been turned back early on. He found Sabrina and Juleka midway through the day, a Milbert's Tortoiseshell and a Anise Swallowtail respectively. His other classmates remained stubbornly missing, though that perhaps wasn't surprising given the sheer number of butterflies there had been.

 _Had been_ and _still were,_ if he was being entirely honest with himself. Or maybe it just seemed that way since he was getting closer to Le Monarque and the butterflies were just naturally denser near the supervillain. He was getting exhausted, more mentally than physically. It was rare for a fight with an akuma to drag on like this, though it had happened a few times before.

He'd always had Ladybug next to him to make the downtime more interesting, though.

Still, it wasn't like he had any other options besides pressing on. The city wouldn't be able to run normally while the Le Monarque still roamed free.

A flurry of butterflies streaming upwards caught Chat Noir's attention. He plastered himself against the wall of the alley he had hidden himself in as he kept a careful eye on the butterflies. Something had disturbed them. Hopefully it was the Le Monarque getting impatient and not a civilian wandering out into the streets or worse, an attack squad sent to sniff him out and bring him back to the akuma.

Even though the butterflies were unnerving him (he was going to punch Hawkmoth right in his stupid face when they finally met for thinking that it was a good idea to have _human sized insects that was so creepy_ ), Chat Noir found himself creeping forward. He felt better being on the offensive anyway, and if any butterflies had spotted him then it was better to just keep on moving. He found himself drawn forward, darting _towards_ the cloud of butterflies instead of away, careful to stay hidden the whole time. Chat Noir stayed on high alert, all of his nerves positively buzzing as he got closer.

He was wound tighter than a tightrope at the circus when a bone-chilling cackle lit up his nerves like lightning.

"You can run and hide but you can't win, kitten," Le Monarque sing-songed, spinning in the middle of the Champs-Elysees in front of the Arc de Triomphe. His cape fluttered behind him in the wind, orange and black catching the sun's light as the fabric twisted. White dots stood out against the thick black lines edging the pattern.

Chat Noir squinted. That pattern on his cape seemed awfully familiar, almost like it was mimicking a butterfly's wing pattern. There was an orange butterfly like that, he was sure of it...

Suddenly it clicked. _Le Monarque._ The Monarch butterfly. Duh.

"Are you looking for your partner?" Le Monarque called out again, stopping Chat Noir dead in his tracks. "Good luck finding her! She's in my butterfly collection now!"

Surely the akuma didn't know he was close by? Chat Noir checked around himself. There weren't any butterflies nearby that could see him. He and Le Monarque hadn't been close together for ages. He didn't have a tracker on him (he had checked).

If the akuma had super-smelling senses, he was going on strike.

His shoulders slumped in relief when the supervillain made a disgusted noise and spat on the ground. "Still not anywhere close, scaredy-cat? You'll have to come here eventually. And Le Monarque will be waiting for you when you do!"

...apparently it wasn't just in movies and cartoons where supervillains liked to monologue to thin air. Le Monarque must just _really_ like the sound of his own voice.

While the supervillain was distracted, Chat Noir took the opportunity to peer around the open square. There were fewer butterflies than he had expected (granted, he had expected every square meter of the ground to be covered in giant butterflies so there was a _lot_ of room for improvement), but dashing out to attack Le Monarque would still be suicide.

As crazy as Ladybug insisted he was sometimes, there was no way Chat Noir was even going to try a run like that.

The butterflies here were drab, like Le Monarque didn't want them overshadowing him and his colorful cape. There were white butterflies and pale yellow ones, a couple in washed-out blue and a handful of drab brown butterflies.

A flash of color caught Chat Noir's eye as he leaned a little further out. One of the butterflies on the Arc de Triomphe itself was a brilliant red, eons more vibrant than any of the butterflies surrounding it. If he ignored the face (that was _not_ getting any less creepy), the butterfly was actually pretty gorgeous.

 _That_ was his Lady, he was sure of it. Why else would Le Monarque keep her so close?

The biggest problem was that there was no possible way he would be able to see the pattern on her wings well enough from his position to identify her species. He would have to circle around and climb up a building, all without being seen, to get into a good enough position to see her.

Praying that she wouldn't move, Chat Noir turned and sprinted off as stealthily as he could. He took the back alleys as much as he could as he moved, just so he could stay out of sight. He was so close to getting Ladybug back (and hopefully wrapping this entire fight up) that there was no way that he was going to risk a misstep now.

Claiming his spot took some time as well. Several butterflies perched on the rooftop Chat Noir wanted to claim as his own, so he had to identify all of them first. Two ended up being random civilians who were startled to be suddenly de-butterflied but who kept calm, and the other was the mayor.

To absolutely no one's surprise, he did not keep calm. Chat Noir had to beat a hasty (temporary) retreat while the butterflies came to investigate. They didn't stay long, much to his surprise. The mayor was shuttled back off to become a butterfly yet again (much to the Mayor's horror, if the yells and threats were anything to go by), and the area fell quiet once again.

It felt like a trap, but there was no other way he could get Ladybug back. Chat Noir would just have to have all of his senses on high alert.

Getting back to his spot took much longer than Chat Noir would have liked- _what if Le Monarque moved her_ \- but finally he managed to wedge himself into a suitable hiding spot behind a chimney and look down at the square. Ladybug had only drifted a couple meters to the left during the chaos, making Chat Noir breathe a sigh of relief. He wasn't in any hurry to repeat that entire performance again.

"All right, time to identify you," Chat Noir murmured, pulling the by now-ratty book out from under his belt. He _really_ hoped that Ladybug's Miraculous Cleaning Light would fix it, because there was no way he wanted to hand a book in this condition back to Mr. Johnson. "Please let there only be one butterfly like this. I don't want to be this close to Butterfly Central any longer than necessary."

There was not only one butterfly species that matched Ladybug. There were several.

Worse yet, when Chat Noir looked up, he saw Ladybug-butterfly fluttering up into the air, drifting in his direction.

 _No time to figure out which one she is. Just guess and hope to be right._

"It's a _Euphydryas editha_ ," Chat Noir guessed blindly, pointing to Ladybug-butterfly. "Please, _please_ be right."

There was no _poof_ of red smoke. Instead, the butterfly, attracted by the movement of his arm, started to move in Chat Noir's direction. He only just resisted the urge to swear.

"No? It's a _Euphydryas chalcedona,_ then!" Chat Noir guessed again, looking at the next species in the book. "No? Really? Oh, come on! How am I supposed to know if I'm getting the species wrong or if I'm pronouncing the scientific name wrong? There's no way to tell the difference!"

No one answered him. He had expected that.

"How are all of these different species?" he continued in panicked frustration when he came upon the third page of seemingly identical butterflies. "What, is one red spot different? Why not just combine the stupid things? They all look the same anyways." He frantically paged back and forth as the butterfly he suspected might be his Lady drifted towards him. The descriptions below the photographs were no help; after all, English wasn't his strongest subject and _for the love of all things holy he did not have time to translate right now._

"This is _ridiculous_ ," Chat Noir muttered, scowling. "Can't it just be one species? It's not like anyone can tell the difference except maybe the butterflies and no one is asking them." Taking a deep breath (the butterfly was getting _really_ close), he pointed again and announced, "It's a _Euphydryas gillettii!_ "

For a long second there was nothing. The butterfly swooped closer, almost on top of Chat Noir's head. He closed his eyes, ready for the worst.

A puff of smoke and the _thud_ of a body landing on top of his forced Chat Noir's eyes back open. He blinked down at himself and met Ladybug's wide, confused eyes.

"Chat Noir? What happened?" Ladybug pushed herself up off of him and looked around, completely disoriented. "Where are we? How did I get here?"

"Careful, my lady. Don't let Le Monarque see you." As gently as he could, Chat Noir tugged her back up against him, out of sight of the still-present akuma. They would be lucky if Le Monarque hadn't noticed Ladybug's disappearance. "You got turned into a butterfly. I changed you back."

Chat Noir was surprised by the force with which Ladybug hugged him. His partner was practically squeezing the life out of him.

"You were a gorgeous butterfly, if that helps any," Chat Noir volunteered in a strangled voice when Ladybug didn't show any signs of letting go. "Except for the face. Those didn't get any less creepy, even after staring at them for hours."

Ladybug finally let him breath again as she loosened her arms and let out a snort at his words. "Are you going to have nightmares after this is over, kitten?"

"Definitely."

Ladybug giggled at that before getting down to business. "Did you have a plan in place? I don't want to throw you off if you did."

"My only plan was to reduce the butterfly army and find you, my lady." Chat Noir flashed a smile at her. "Beyond that, my only plan was to not get caught."

"Well, you did that." Ladybug glanced over her shoulder. "Maybe we should retreat and regroup and you can catch me up on what you've been doing. I don't know how long the fight has been going on-"

"Hours," Chat Noir supplied helpfully.

"-but we should probably wrap it up soon." Ladybug glanced up at the sun and let out an exasperated sigh. "At least lots of people have been missing all day. I don't think I would have been able to come up with an excuse for missing so long."

Chat Noir nodded in agreement as they started their careful retreat. "Yeah. As much as I hate these kinds of akumas, I like having a premade excuse for missing for long periods of time."

They fell quiet as they crept past a group of resting butterflies before darting down into a metro station. It was cooler down below the ground, which meant that the heat-loving butterflies would be staying away.

"What time is it now?" Ladybug asked, glancing around the station. There weren't any clocks on the walls. "You said it's been hours, but, like, two hours? Three?"

"Four, maybe?" Chat Noir guessed. "It was lunchtime a while ago. My kwami got to eat, but I didn't."

Ladybug ignored his kitten eyes as she gasped. _"Four?_ That's awful! I'll use Lucky Charm as soon as we go back out. How big is the butterfly army?"

Chat Noir grinned and straightened up proudly. "It's mostly just down to the butterflies around Le Monarque. That's what I've been doing all afternoon- freeing butterflies."

"Good job, _chaton_!" Ladybug praised, reaching over for a coveted chin-scratch. Chat Noir leaned into it happily but as always, it ended far too soon. "Okay, so we have a smaller army to deal with, but one or two butterflies by themselves could seriously get in the way of our fighting."

"We could always try to lure a couple away from Le Monarque at a time," Chat Noir suggested. "Otherwise he could just turn them back into butterflies."

Ladybug was frowning. "We could, but that could take a while. Maybe we should wait on a plan until we see what my Lucky Charm is." Not like they ever really did it any other way.

"Planning on the fly? I like it!" Chat Noir was already on his feet and headed for the stairs. He only paused for a moment when a butterfly's shadow slid over the stairs. "Uh, do you want to maybe head to a different station to head back up? I think maybe Le Monarque's gotten closer."

Ladybug gave a quick nod of agreement as more butterflies flew over the station and together, they tore away down the empty tunnels. Ladybug led the way, since she was more familiar with the metro system than Chat Noir was.

"This has been _such_ a long day," Chat Noir panted as they tore past the next station. Ladybug, ever the cautious one, had apparently decided to go several stations' distance away to make sure they wouldn't be hit by Le Monarque the second they poked their heads above ground. "I'm going to need to eat the second we finish."

"Head in the game, Chat Noir," Ladybug called over her shoulder. She vaulted up onto the platform the second it came into view. "Fight now, food later."

"I've been saying that for over two hours now," he grumbled, but followed regardless. They tore up the metro station's steps, winced as the sun's glare nearly blinded them, and came to a slightly unsteady stop.

"It's all clear," Ladybug said, glancing around. Without hesitating, she grabbed her yo-yo and tossed it up in the air. "Miraculous Ladybug!"

There was a flash of light, and then a large container tumbled down out of the air. Ladybug only just managed to catch it before it hit the ground. Backpack-like straps dangled from one side, and a hose and nozzle came off the other side.

"What is that even?" Chat Noir asked in confusion as Ladybug inspected the tank and the nozzle on it. "What are we supposed to do with it, throw it at the akuma?"

"I don't think so. If it were just for that, it wouldn't have all of this extra stuff on it." Ladybug pushed a button experimentally, releasing a small cloud of gas. She stuck her hand into it and immediately recoiled, nearly dropping the can in the process. "Ugh! It's _freezing!_ "

Chat Noir perked up, interested. "It's freezing? Really?" He waved his hand through the remnants of the cloud. He could just feel the icy bite of the gas through the material of his suit. "Liquid nitrogen! That's super cool!" He grinned. "Quite literally."

"Funny, funny." Ladybug hoisted the container onto her back and adjusted the straps. "I guess we'll have to get closer and figure out how to use it on the fly." She sighed. "As usual."

They had been so focused on the liquid nitrogen that they didn't notice the pale grey butterfly floating slowly closer until it was practically on top of them. Both superheroes yelped and ducked, trying to twist away from the giant insect. Ladybug sprayed the gas at the butterfly blindly, trying to create a bit of a distraction for them to get away.

What they didn't expect was the butterfly's wings locking up and the insect dropping to the ground like a stone. Even as they stared, it didn't move.

"Oh," Ladybug breathed. "Butterflies can't fly when they get too close. We take out Le Monarque's butterfly army like that."

" _Purr_ fect," Chat Noir said cheerfully. "So you'll spray and I'll go after the clipboard? That has to be what the akuma is hiding in."

Ladybug's response was a sharp nod, and then they were off again. It didn't take long for Ladybug to figure out that she could shoot the liquid nitrogen in a narrow, far-reaching stream by adjusting the nozzle, letting her take out butterfly after butterfly in quick succession as they charged forward. Any butterflies that rose up to challenge them were taken down by a quick squeeze of the trigger on the gas tank. Adrien wasn't fully convinced that liquid nitrogen normally behaved that way (his memories of it from a homeschool science unit mostly involved a chilly cloud and Nathalie swearing up a storm when it hit her skin. She took him out for ice cream as a bribe to not tell his dad.), but he supposed that kwami magic probably played a big role in making the gas behave in the way it did.

They didn't know how long it would take for the butterflies to recover. There was no time to look back or waste a second though on it.

"I see Le Monarque up ahead," Chat Noir called as he dodged a falling butterfly. "He looks furious and there aren't any butterflies up there. I think he sent them all this way to try to take us down before we got to him."

As much of a pain as army-making akumas were, they always tended to be significantly weaker in one-on-one fights. Their ability to fight was concentrated in their army, not in them. There were exceptions, of course, but

"We still have to get close to him without getting turned into butterflies," Ladybug pointed out. "Maybe we can use the gas to confuse him. We'll just have to make sure that it doesn't blind us more than him."

Chat Noir winced. Yeah, liquid nitrogen and bare, exposed eyes...yeah, not good. Unless it wasn't _them_ getting it in their eyes.

"Maybe spray it right in his eyes," Chat Noir suggested. It was cruel, but it wasn't like Le Monarque would remember it after Ladybug's Cleaning Light. "That'll blind him long enough for use to get close, but hopefully won't use enough gas to get in our way."

Ladybug gave a sharp nod to show that she had heard, but didn't pause to respond.

"Oh, so the little superheroes have come out of hiding!" Le Monarque taunted, readying his clipboard. His fingers raised, ready to swipe and send the all-too-familiar beams of light at them. "Ready to come and fight me?"

"Ready to stop hiding behind your butterfly army?" Chat Noir called back. "You weren't doing your own fighting before. We were just evening the playing field."

Le Monarque snarled and the heroes charged. They dodged back and forth as he sent flashes of light at them but never hit. With a yell, Ladybug shot a short spray of the liquid nitrogen at him.

Le Monarque flinched just long enough for the heroes to get closer. The second his head came back up, Ladybug darted in and sprayed again, aiming for the eyes. Chat Noir winced in misplaced sympathy- there was a _reason_ people wore protective goggles when working with liquid nitrogen- before he quashed his reaction and joined Ladybug, ready to take any hits if Le Monarque recovered faster than they expected.

Except he wasn't behaving like they expected, not at all.

Instead of doubling over in frozen-eyeball hell, Le Monarque was moving in almost slow motion. His arms were coming up to grasp at his face, but they were moving incredibly slowly through the cloud of gas that surrounded him. The longer he was in contact with the liquid nitrogen, the slower he moved. The purple outline of Hawkmoth's mask flickered in and out of focus over Le Monarque's face, like the connection wasn't quite working.

"Chat Noir, knock the clipboard out of his hand!" Ladybug called, dancing around Le Monarque with her gas nozzle clutched tightly in her hands. Her earrings gave a sharp beep- was that the four minute warning, or the three? "I don't want to get too close; ladybugs react the same way to the cold as butterflies do. My hand seized up earlier when I stuck it in the nitrogen."

Chat Noir didn't even wait for her explanation to end. Extending his baton, he swung towards Le Monarque and swatted the clipboard out of his practically-frozen hand. It was practically child's play, with Le Monarque frozen the way he was. The clipboard clattered to the ground and slid, coming to a stop at Ladybug's feet.

Ever so slowly, Le Monarque's hand reversed course, reaching out to grab for his clipboard. Too slow.

Ladybug stomped down on the possessed clipboard, snapping it into pieces. The akuma fluttered upwards for only half a second before Ladybug caught it in her yo-yo.

"Thank everything holy," Chat Noir sighed as Ladybug released the purified butterfly seconds later. He stepped forward to help her get her Lucky Charm off of her back. She tossed it into the air as though it weighed nothing and they fist-bumped as her army of glittering ladybugs swarmed throughout the city, turning butterflies back into people and repairing the damage that Le Monarque had caused. The sound of faint cheering carried through the air, making both heroes grin. It wouldn't take long for Paris to get back to normal.

"I should get back to my class," Chat Noir said as Ladybug's earrings beeped again. He shot her a concerned look. "Will you be able to get back to wherever you came from before your time runs out?"

Ladybug waved off his concern. "No, but people have been misplaced all across the city because they were turned into butterflies. It'll make my story more believable if I turn up all the way over here." She smiled at him. "I'll talk to Mr. John- er, the akuma victim- and then find somewhere to detransform. You go on ahead."

Chat Noir left with a salute and a wave. He wasn't in too much of a rush since he hadn't used Cataclysm and really, did he _have_ to get all the way back out to the butterfly gardens by himself? Like Ladybug had said, her army of ladybugs hadn't brought people back to where they had been (though it seemed to have at least managed to get people off of rooftops, something that Chat Noir was very thankful for). Most everyone who had been a butterfly had ended up far from their original location.

So it would only strengthen his excuse if he were suddenly back in the city, kilometers away from where he was supposed to be.

It didn't take long at all for Chat Noir to detransform back into Adrien, and it only took minutes for the Gorilla to pick up Adrien after being called. Even though he wanted nothing more than to stop by home for something to eat, Adrien resisted the urge to ask. He had his lunch in his bag at the gardens, and it was fully possible that people who had actually been turned into butterflies hadn't even realized that they had missed lunch.

"Wait, pull over for a second," Adrien suddenly blurted as they passed a pedestrian on the sidewalk. "That's one of my classmates."

The Gorilla obediently pulled to a stop and Adrien didn't waste any time rolling down his window and waving to Marinette as she came up the street. She waved back as soon as she noticed him.

"Did you get turned into a butterfly too?" Adrien asked as she approached the car. "Do you want a ride back out to the butterfly gardens? I left my bag out there."

Marinette beamed at him. "Oh, that would be great! My bag is out there too, and maybe we can finish up the worksheet. Can we stop by the bakery first, though? I wanted to make sure my parents are all right."

The Gorilla nodded, and five minutes later they were pulling away from the bakery, each armed with a delicious pastry provided by Marinette's parents. The Gorilla was humming happily as he nibbled away at his raspberry-filled pastry as he drove. Adrien had only just managed to refrain from scarfing his own treat down when he got it.

"Have you seen anyone else from our class?" Adrien asked as the Gorilla pulled onto the highway and sped up. "I'm guessing people ended up all over the place."

"I saw Chloe going into her father's hotel," Marinette said as she licked powdered sugar off the tips of her fingers. "And I passed Rose. She had her bags when she got hit, so she wasn't going to go back. She also said that she and Nino had started with the identification stuff, so they could do the rest at school."

Adrien winced.

Right. _That_.

At least they only had to do five butterflies. It wouldn't kill him.

The project that Madam Mendeleiev assigned the next day- identifying 100 Eurasian butterflies, due in a week's time-just might.

* * *

 _This story is now complete! I hope you enjoyed it._


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